TPT September 2008

T echnology U pdate

New ‘RidgeLock’ solution for HVAC manufacturer

AddisonMckee, has designed, built and supplied two RidgeLock machines for one of America’s largest manufacturers of heating, venting and air conditioning products (HVAC). In a typical domestic or commercial heating system, a heat exchanger is used to transfer heat generated by burning oil or gas to the air for distribution. The heat transfer tubes contained within the system require precise sealing to the heat exchanger panel in order to prevent the escape of gases, and this is  AddisonMckee has supplied two RidgeLock machines to a US HVAC company

normally done by means of a ‘RidgeLock’. In the AddisonMckee RidgeLock process, expandable segmented tooling is inserted into the heat exchanger tubes (bent at 180° into a sheet metal panel) in order to create a rim that acts as a secure lock between the tubes and panel. For the customer in question, one AddisonMckee RidgeLock machine has been designed to perform locking operations for small inner tubes (1.75" OD x 0.4" wall aluminised mild steel or stainless), and the other machine performs the locking operation on larger outer tubes (2.25" OD x 0.4" wall aluminised mild steel or stainless). Both machines have been designed to hold two sets of tools – one each for the end of the tubes. A roller table located between the two machines assists in conveying the component assemblies. AddisonMckee RidgeLock machines are designed to perform locking operations by use of a manual set up feature of a micrometer stop nut on the cylinder to control the machine. Tubes are expanded

by use of segmented fingers and a tapered mandrel inside the tube to lock the tube to the heat exchanger plate. The heat exchanger assembly being ridge-locked is then progressed manually along the conveyor table between machine cycles. In the ridge-locking process, the heat exchanger plate is held down by electric magnetics. The operator then positions the tube in an alignment guide that holds the tubes vertically during the forming process. Air cylinders are then activated at the end of the forming cycle to lift the plate assembly off the tools and assist the movement between cycles.  The machines are used to perform locking operations on heat exchanger assemblies

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S eptember 2008

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